Morphological Classification of Corrupted Colonic Crypts in Ulcerative Colitis

Abstract

In ulcerative colitis (UC) the colonic mucosa shows, in addition to a high number of inflammatory cells, crypts with architectural distortions, called corrupted colonic crypts (CCC). Here we classify the histologic repertoire and assess the frequency of CCC in UC. Five-hundred and sixteen histologic sections from 29 colectomy specimens with UC (24 having adenocarcinoma and five, high-grade dysplasia, HGD) were reviewed. The vast majority of the colonic mucosa portrayed countless crypts with normal shapes (CNS) lined with normal epithelium, except for 45 CNS: 28 showed inconclusive-suspected cellular changes (ISCC), and 17, high-grade dysplasia (HGD). CCC were subdivided into four groups: i) Crypts with fission distortions, ii) Crypts with length distortions, iii) Crypts with outline distortions and iv) Crypts with axial polarity distortions. The most frequent CCC group had axial polarity distortions (33.4%), and the less frequent CCC group, outline distortions (21.1%) (p<0.05). No apparent differences in frequency between groups were found in colectomies with HGD/carcinoma, or in colectomies preformed for medically-refractory UC without HGD/carcinoma. Out of the 902 CCC present in the specimens, 343 (38.0%) displayed ISCC, 186 (20.6%) HGD, and the remaining 373 (41.4%) normal epithelium. Hence, of the 203 crypts exhibiting HGD, 186 (91.6%) were CCC and the remaining 17 (8.4%) CNS (p<0.05). Based on these findings it is suggested that the microscopic search for HGD in UC colectomy-specimens should preferentially be focused on mucosal areas exhibiting CCC. This view is validated by recent findings showing that p53 overexpression (a biomarker of epithelial carcinogenesis) significantly correlated with architectural distortions of the crypts in UC.